package code.D1216;

/**
 * author : yeswater
 * date : 2023/12/16
 * 
 * 翻转二叉树 easy
 * 
 */

public class T226 {
    public TreeNode invertTree(TreeNode root) {
        if (root == null) {
            return root;
        }
        TreeNode tmp = root.right;
        root.right = root.left;
        root.left = tmp;
        invertTree(root.left);
        invertTree(root.right);
        return root;
    }
    
    private static class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;
        
        TreeNode() {
        }
        
        TreeNode(int val) {
            this.val = val;
        }
        
        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }
}
